EP3439889A1

EP3439889A1 - Inkjet printer for labelling goods having a writing head and having a storage vessel

Info

Publication number: EP3439889A1
Application number: EP17716832.5A
Authority: EP
Inventors: Andreas Slomianny
Original assignee: EBS Ink Jet Systeme GmbH
Current assignee: EBS Ink Jet Systeme GmbH
Priority date: 2016-04-06
Filing date: 2017-04-06
Publication date: 2019-02-13
Also published as: EA034632B1; CN109070602B; KR20180126498A; WO2017174708A1; US10525732B2; IL262113A; US20190111707A1; CN109070602A; MX2018011572A; CA3017045A1; JP2019513599A; EA201891892A1

Abstract

The inkjet printer for labelling goods has a writing head (20) which has a at least one outlet opening (26) for ink droplets, b a printing unit (78) which is connected to said outlet opening, c a compressed air pump (70) and d an electric controller (32). It has at least one storage vessel (40) for liquid which flows through the outlet opening. The storage vessel is connected releasably to the writing head in a coupling region. A first pressure sensor (80) is arranged on the compressed air line (76) in the writing head, which first pressure sensor (80) detects the air pressure in the compressed air line and outputs an air pressure signal to the controller (32). A second pressure sensor is arranged on the ink line, which second pressure sensor detects the pressure in the ink line and outputs an ink pressure signal to the controller. The latter outputs an _"Ink empty" signal if the ink pressure signal drops by more than 10% with respect to the air pressure signal.

Description

Ink jet printer for labeling goods with a writing head and with a storage container Ink jet printer for labeling goods with a writing head, a) at least one outlet opening for ink droplets on a front surface, b) a printing unit connected to the outlet opening, c) a compressed air pump and d ) has an electrical control, and with at least one reservoir for liquid flowing through the outlet opening, such as An ink, pigment or solvent, wherein the reservoir is releasably connected to the write head in a coupling region and has a housing and a foldable bag located in this housing, in which the liquid is housed and which via an ink line which is guided through the coupling region , connected to the printing unit, the compressed air pump is connected via a compressed air line to the space between the housing and the bag and pressurizes this space with overpressure.

The invention preferably relates to such inkjet printers in the form of handheld devices, see e.g. B. WO2013 / 120702 AI, it can also in stationary devices, see, for. B. EP 1 064 153 Bl, find application. Handsets are self-sufficient, they are such as cordless screwdriver with an internal voltage source, in particular accumulator, equipped. In stationary devices, the power supply is usually from the outside, for example via the normal power grid. The liquid required for the printing process is in the storage container. For this purpose, reference is made to WO 2013 / 120702A1, the disclosure of which belongs to the disclosure content of the present application in its entirety and is included in this respect. The reservoir must be replaced in practical operation relatively frequently, since the liquid is constantly consumed in printing and the stock is exhausted after a certain number of printing operations. Therefore, the reservoir is designed so that it can be easily replaced. It can be released from the write head at the coupling area. When uncoupling, the ink line and the compressed air connection are interrupted. Storage container with an internal bag which receives the liquid and one located between the bag and the housing of the reservoir Compressed air space have the advantage that the required for the printing hydraulic pressure is achieved by pneumatic pressure or can be. As a rule, the liquid does not pass through a liquid pressure pump in which deposits etc. could form.

A disadvantage of the prior art ink jet printer is that whenever the ink supply in the bag runs out, the printed image deteriorates. There is no simple proof that the ink supply is running out. Therefore, there is a desire to deliver a blank signal for ink at the right time.

This is where the invention begins. It has set itself the task of continuing to form the ink jet printer of the type mentioned in that an empty signal for ink can be generated. This should be done with simple means. The blank signal should preferably be output before the print image gets worse.

On this basis, the invention solves this problem on the basis of the features of the preamble of claim 1, characterized in that in the write head of the compressed air line a first pressure sensor is assigned, which detects the air pressure in the compressed air line and emits an air pressure signal to the controller that the ink line in Assigned to the write head is a second pressure sensor there detects the pressure in the ink line and emits an ink pressure signal to the controller, and that the controller outputs an "ink empty" signal when the ink pressure signal by more than 3, preferably more than 5% compared to Air pressure signal drops.

The invention proposes to detect both the pressure generated by the compressed-air pump and the pressure present in the ink conduit, and to compare them with one another. The output signal is the ratio of the two pressure values, which is present in normal operation when there is certainly sufficient ink available. In normal operation, the air pressure in the compressed air line is slightly higher than the fluid pressure in the ink line because a small portion of the air pressure is used to fold the bag, etc. In normal operation, the ratio of air pressure signal and ink pressure signal is determined and recorded as the base value , If the ink pressure signal drops, it means that the ink supply is running out. It is with increasing Draining the bag requires more and more air pressure energy to fold the bag, resulting in a loss of ink pressure. In particular, however, the pressure in the ink line is reduced by the fact that the bag is essentially pressed out. The invention has the advantage that an empty signal "ink empty" can already be dispensed before the printed image deteriorates.

It is advantageous to monitor the air pressure signal independently of the ink pressure signal to the effect that there is always sufficient air pressure, in particular that the air pressure signal is substantially constant. For example, a fault in the compressed air supply can also be detected. Erroneous ads can be avoided.

The air pressure can be measured from its generation in the compressed air pump to the point where the compressed air line runs through the coupling area. Detecting the air pressure in the compressed air pump itself, if not the compressed air pump already provides such a detection, associated with effort. It is therefore advantageous to measure between the compressed air pump and the point at which the compressed air line passes through the coupling region. It is measured where the compressed air line is easily accessible.

In practical training, the compressed air line ends in the coupling area. The coupling area has an external seal. As a result, a separate single clutch for the compressed air line is not necessary. An outer surface of the reservoir limits the compressed air space of the reservoir. With a storage container that is not connected to a write head, the space between the airtight housing and the bag is there to the outside open.

The invention has the advantage that all measures necessary for the measurement can be carried out in the write head. All sensors are located in the write head. There are no interventions in the reservoir necessary. The reservoir can be used as known in the art.

As sensors for detecting the pressures conventional, marketable sensors can be used, such as piezo elements, pressure boxes and the like. The amount by which the ink pressure signal must drop from the air pressure signal until the signal "ink empty" is output is arbitrary and can be adjusted and selected depending on the rigidity of the bag, the size of the pressure chambers, etc. In which period Depending on the control, it is well within the scope of the invention for the signal to be averaged over a certain period of time until the "empty ink" signal is output, for example a few seconds. This makes it possible to exclude short-term events caused by any disturbances.

It is advantageous that in the control the empty signal "ink empty" is output only when the ink pressure signal has dropped over a period of time greater than zero, in particular at least 0.5 to 3 seconds relative to the air pressure signal.

It is possible to combine individual coupling devices, e.g. to combine the mechanical coupling and the fluid coupling into a single clutch. Further advantages and features of the invention will become apparent from the other claims and from the following description of two non-limiting embodiments of the invention, which are explained in more detail below with reference to the drawing. 1 shows a perspective view of an inkjet printer as an assembly picture with a main device and a reservoir located at a distance from it, FIG.

Fig. 2: a view in the axial direction, seen from the separation plane in

1, on the storage container,

3 is an axial view, seen from the separation plane and in the opposite direction to Figure 2, on the main unit, Fig. 4 shows a sectional representation of the storage container of a second exemplary embodiment, as seen along a sectional plane such as IV-IV in FIG. 2 and FIG. FIG. 5: a partial sectional view as along the sectional plane as VV in FIG. 3 for an end piece of the main device for the second exemplary embodiment.

The inkjet printer for labeling goods according to the two embodiments is designed as a handheld device. He has a main unit 20, which is formed here substantially cylindrical with attached handle 22. On the in Fig. 1 right side of the main unit 20 is a front surface 24, where several outlet openings 26 are provided for ink 49. The ink discharge takes place in accordance with the arrow 28. Preferably, ink droplets are printed. In the handle 22, a power supply 30 is housed, it is shown as an accumulator. It is connected to a controller CON 32, which controls all operations. In the handle 22, a trigger 38 is attached, with it a printing operation is triggered. Separated by a dividing plane is located in Fig. 1 to the left of the main unit 20 a reservoir 40. He has its own housing. This is limited by a flat container wall 42, which has the shape of a circular disk, and by an airtight cap 44. Both are connected to each other airtight. The limited by them interior communicates via a hole 46 with the environment. The hole 46 is located in the container wall 42.

In the interior of the storage container 40 is a bag 48 for ink 49. It is made of a foldable, thin material, for example of a plastic film. Its internal volume varies with the amount of ink 49, is only liquid, z. B. ink 49 and is connected only via a second coupling part 50 with the outside world. This second coupling part 50 is designed as a socket and cooperates with a first coupling part 52, which projects transversely to the separating plane on the main device 20 and is designed as a plug. The two coupling parts 50, 52 allow in the assembled state, a liquid-tight connection. The two coupling parts 50, 52 are rotationally symmetrical about an axis 54. As shown in FIGS. 1 and 5, the first coupling part is 52 is connected within the main unit 20 with an ink conduit 56 which is formed here as an ink tube. Dad urch the interior of the bag 48 is only accessible if the two coupling parts 50, 52 are connected to each other. The two coupling parts 50, 52 and the ink line 56 form an ink supply line, which is interrupted when uncoupling the coupling portion.

The second coupling part 50 is formed so that it seals itself when the first coupling part 52 is not in the second coupling part 50. This ensures that the interior of the bag 48 is closed when the coupling 50, 52 is opened and thus separated, as shown in Figure 1. Fig. 4 shows a corresponding, self-closing valve. This preferably also at the same time a seal between the two coupling parts 50, 52 ago, when the clutch 50, 52 is closed.

On the ink tank 40, a seal 74 is arranged. It is held on the outer edge of the container wall 42 and thus in the immediate vicinity of the edge of the cap 44. It is ring-shaped. In an alternative, it is arranged on the main unit 20. At the ink tank 40 three hooks jump forward. They are within the seal 74. Together with correspondingly formed pockets, they form a mechanical coupling device 66, 68. The pockets are also located inside the seal 74. The pockets are an exemplary embodiment of a first coupling means 66; second coupling means 68 of the mechanical coupling device 66, 68. Other embodiments of the coupling means are possible. Thus, a coupling agent may be designed, for example, as an external thread, the other as an internal thread. It is also possible to form the coupling means 66, 68 as a bayonet or click connection. A kinematic reversal is possible, please include.

In another embodiment, the hooks constituting the second coupling means 68 of the mechanical coupling device 66, 68 in the first embodiment shown are arranged in a kinematic reversal on an end wall 64 of the main device 20 opposite the container wall 42, and the pocket-shaped first coupling means 68 is in position the container wall 42 is formed. It is possible to form the pocket-shaped first coupling means 66 on the container wall 42 and not airtight. Thus, the first coupling part 52 can take over the task of the hole 46. If the coupling means 66, 68 are airtight, they may be located inside or outside the periphery of the seal 74.

When the coupling means 66, 68 are located outside the periphery of the seal 74, it is necessary that they be made airtight, e.g. have airtight pockets. This is not necessary with an arrangement within the device 74. Outside the seal, the housing of the reservoir 40 is airtight.

As shown in FIGS. 1 and 5, inside the main unit 20 there is a compressed air pump 70 or another suitable air pressure generator. Devices are used, such as e.g. in portable sphygmomanometers. The compressed air pump 70 is controlled by the controller 32 and is connected thereto. An output-side compressed air line 76, which is designed as a tube, opens into an air passage 72, which is located in the end wall 64 of the main unit 20. The air passage 72 is disposed inside the gasket 74. When the compressed air pump 70 is turned on, it sets the gap between the end wall 64 and the container wall 42 under overpressure. Through the hole 46 or an equivalent passage, e.g. Bags communicates this gap with the interior of the ink tank 40. Thus, there is an overpressure in the interior. Due to this overpressure, the bag 48 is compressed, the ink 49 is thereby under overpressure.

The ink conduit 56 connects the first coupling part 52 with a printing unit 78. This is associated with the outlet openings 26. The printing unit 78 has, for example, at least one valve not shown here, the z. B. controls the printing process and is a standard part of an ink printer, or provides continuously ink droplets ready. In this way, the printing process is enabled. Other printing methods are possible. Due to the overpressure in the ink container 40, it is ensured that the ink 49 can be transported at least into the main unit 20 without having to suck in or otherwise convey the ink 49. Advantageously, the overpressure is sufficient for the printing process. This can be dispensed with an additional pressure increase. The compressed air line 76 is associated with a first pressure sensor 80. He is z. B. attached to her. It is generally arranged so that within the main unit 20, the pressure value of the air pressure generated by the compressed air pump 70 is detected. The first pressure sensor 80 is connected to the controller 32. It outputs an air pressure signal to the controller 32.

The ink conduit 56 is associated with a second pressure sensor 82. He is z. B. attached to her. It is generally arranged so that within the main unit 20, the pressure value of the liquid originating from the bag 48 is detected. The second pressure sensor 82 is connected to the controller 32. It outputs an ink pressure signal to the controller 32.

The controller 32 processes these two pressure signals. They are compared constantly or at certain intervals. An "empty ink" signal is output when the ink pressure signal drops by more than 2, possibly more than 3, preferably more than 10%, from the air pressure signal. A display 84 disposed on the main body 20 outputs a corresponding signal. Other indications are possible If the current supply of liquid in the bag 48 is relatively low, so that it may no longer be sufficient for a printing operation, this will be displayed and the printing process may then be blocked.

The described arrangement of the seal 74, the fluid coupling with the coupling parts 50, 52 and the mechanical coupling with the coupling means 60, 68 forms a coupling region. Through him, the reservoir 40 is detachably connected to the write head 20.

Preferably, the container wall 42 and the end wall 64 are bounded outwardly by a circular line which is centered to the axis 54. This is so embodied in the embodiments. Preferably, the mechanical coupling operates by a rotational movement about a certain angular range, for example 10 to 40 °. Preferably, it is designed as a bayonet connection, as indicated in the exemplary embodiment. The second embodiment of Figures 4 and 5 has all the features of the first embodiment of Figures 1 to 3. The second embodiment differs from the first embodiment by the following additional elements, which are indicated in the following four paragraphs:

On the end wall 64 of the main unit 20, an annular first antenna 36 is arranged. It is connected to a base unit 34, which is arranged in the main unit 20 and is connected to the controller 32. On the inner surface of the container wall 42, an annular second antenna 58 of a transponder 60 is attached. To this transponder 60 further includes a control unit 62. The transponder 60 cooperates with the base unit 34. It is designed and tuned to this base unit 34. Such cooperative units of a base 34 and a transponder 60 are known in the art, see US 7,520,429 B2; US 4,862,160 A and US 2009/016049 AI. Such units of a base unit 34 and a transponder 60 are often referred to as an RFID system. The base unit 34 not only reads, it also sends information to the transponder 60 and receives replies from it. It can both send and receive. In the present case, the transponder 60 is a so-called passive transponder 60, it does not have its own power supply. He is powered by the base unit 34 with energy. In this case, it is favorable that the antennas 36, 58 of both devices are preferably coaxial and have substantially the same radial extent. They should be coupled as well as possible. This is illustrated in the figures. In the control unit 62, data on the ink 49 are stored in the bag 48, this data includes the expiration date of the ink 49 or other liquid, their type, composition, starting amount and actual amount or amount of ink 49 removed. Further features can be stored , If the respective current amount of ink 49 is known, it is possible to work with different ink containers 40, that is, to exchange them during operation. This is necessary, for example, if you want to print with a different color. The RFID systems are standardized according to ISO-18000-1 etc. Reference is made to this standard. In the controller 32 and / or in the base unit 34 instructions are stored, with which the data contained in the control unit 62 can be compared and processed. If, for example, the expiration date of the ink 49 is exceeded, no printing process is enabled, but preferably a corresponding message, possibly a red blinking display, is triggered. In this sense, the other data are processed or used. In that regard, reference is made to the already mentioned above three EP patents and the WO publication. If, in the exemplary embodiment shown, the antennas 36, 58 are each designed and illustrated as an annular disk, this is not to be understood as limiting. The antennas 36, 58 can also have other shapes, for example they can form a polygon, be oval or star-shaped. The decisive factor is that they leave a sufficiently large interior, so that there is a coupling member 50 and 52 can be arranged.

The ink jet printer for the labeling of goods has a writing head 20, the a) at least one outlet opening 26 for ink droplets, b) connected to this outlet opening 26 printing unit 78, c) a compressed air pump 70 and d) has an electrical control 32. He has at least one reservoir 40 for liquid flowing through the outlet opening 26. The reservoir 40 is detachably connected to the write head 20 in a coupling region. In the write head 20, a first pressure sensor 80 is disposed on the compressed air line 76, which detects the air pressure in the compressed air line 76 and an air signal signal to the controller 32 outputs. On the ink conduit 56, a second pressure sensor 82 is arranged, which detects the pressure in the ink conduit 56 and emits an ink pressure signal to the controller 32. This will output an "ink empty" signal if the ink pressure signal drops more than 10% from the air pressure signal.

Terms such as substantially, preferably, and the like, and possibly statements to be understood as inaccurate, are to be understood as meaning that a deviation of plus or minus 5%, preferably plus or minus 2%, and more preferably plus or minus one percent of normal value is possible. LIST OF REFERENCE NUMBERS

20 main unit

22 handle

24 front surface

26 outlet opening

28 arrow

30 power supply

32 control

34 base unit

36 annular first antenna

38 triggers

40 storage tanks

42 container wall

44 cap

46 holes

48 bags

49 ink, liquid

50 second coupling part

52 first coupling part

54 axis

56 ink line

58 annular second antenna

60 transponders

62 control unit

64 end wall

66 first coupling agent

68 second coupling agent

70 Compressed air pump, air pressure generator

72 air passage

74 seal

76 compressed air line

78 printing unit

80 first pressure sensor

82 second pressure sensor

84 Display

Claims

1

2017/174708 PCT / EP2017 / 058221

claims

Inkjet printers for the labeling of goods

- With a write head (20), the a) at least one outlet opening (26) for ink droplets on a front surface (24), b) connected to this outlet opening (26) printing unit (78), c) a compressed air pump (70) and d ) has an electrical control (32), and

- With at least one reservoir (40) for liquid flowing through the outlet opening (26), such as. Ink (49), pigment or solvent, wherein the reservoir (40) is releasably connected to the write head (20) in a coupling region and a housing and a housing located in this case (48), in which the liquid is housed and the via an ink line (56) which is guided through the coupling region, with the printing unit (78) is connected, the compressed air pump (70) is connected via a compressed air line (76) with the space between the housing and bag (48) and acted upon this overpressure

characterized in that in the write head (20) of the compressed air line (76) is associated with a first pressure sensor (80) which detects the air pressure in the compressed air line (76) and an air pressure signal to the controller (32) outputs that in the write head (20) the ink conduit (56) is associated with a second pressure sensor (82) which detects the pressure in the ink conduit (56) and delivers an ink pressure signal to the controller (32), and that the controller (32) outputs an "ink empty" signal, when the ink pressure signal falls by more than 5, preferably more than 10% relative to the air pressure signal.

Inkjet printer according to claim 1, characterized in that the first pressure sensor in a freely accessible area of a hose of the compressed air line (76) is arranged and / or that the second pressure sensor in a freely accessible area of a hose of the ink conduit (56) is arranged. 2

2017/174708 PCT / EP2017 / 058221

Ink jet printer according to one of the preceding claims, characterized in that, in a normal operation, in which there is certainly sufficient ink (49) in the bag (48), the ratio of air pressure signal and ink pressure signal is determined and stored as normal value in a memory of the controller (32). is stored.

Ink jet printer according to one of the preceding claims, characterized in that in the controller (32), the empty signal "ink empty" is issued only when the ink pressure signal during a period greater than zero, in particular at least 0.5, preferably at least 3 seconds relative to the air pressure signal has fallen off.

Ink jet printer according to one of the preceding claims, characterized in that the air pressure signal in the controller (32) is constantly detected, and that a fault signal is output when the air pressure signal deviates from a usual value by at least 5%, in particular during a period of time zero, in particular at least 0.5, preferably at least 3 seconds has fallen from the usual value.

Inkjet printer according to one of the preceding claims, characterized in that the coupling region has an external seal, that the housing of the reservoir (40) has a container wall (42), at least part of which is located within the seal and that this part has an opening , through which the space between the bag (48) and the housing of the reservoir (40) is accessible.